Preheat your oven to 400 degrees F. Place your Dutch oven with lid in your oven to preheat along with the oven.
In your KitchenAid, mix the flour, harvest grains blend, baking soda and salt.
Make a well in the center and add the starter, butter, honey and milk. Pour the mixture into the dry ingredients and use your dough hook to mix just until combined. The mixture will be stiff. If it is still too crumbly, add another Tablespoon or two of milk or sourdough starter.
Turn the dough out on the counter. Knead it several times to make sure it comes together. Shape it into a round loaf. Slash the top diagonally to make two incisions.
Remove the Dutch oven from your preheated oven. Place the loaf on parchment and gently lift into your Dutch oven. Place the lid back on the Dutch oven and bake at 400 degrees for 20 minutes. Remove the lid and continue to bake at 400 degrees F for an additional 20 minutes until a toothpick inserted in the center comes out clean.
Brush the top of the loaf with melted butter, if desired.